Derek Jeter prepares to bat in the first inning against the Boston Red Sox at Fenway Park on August 3, 2014.

By DAVID LENNON

If everything goes according to plan, Thursday night will be Derek Jeter’s final game at Yankee Stadium.

But it also could close the curtain on his 20-season career, should Jeter decide to say his last goodbyes in the Bronx rather than at Fenway Park this weekend.

If the game does come off as scheduled, Jeter still hasn’t revealed whether he intends to play in Boston. But a source said yesterday that Jeter is likely to DH at Fenway, saving his final appearance at shortstop for the Bronx.

Or a third scenario: Thursday night’s game may not happen at all.

With heavy rain in the forecast, there is the possibility that Wednesday’s 9-5 loss to the Orioles — which ended with Jeter standing in the on-deck circle — will endure as his swan song as a Yankee, or at least in New York.

No wonder he didn’t know what to think heading into what figures to be an emotional cyclone Thursday in the Bronx. Minutes after the Yankees were eliminated from playoff contention, Jeter had trouble sorting through what was churning inside him.

“Right now, it feels bad,” he said. “That’s the bottom line. I can’t tell you what tomorrow is going to feel like. I really can’t. But right now, it doesn’t feel good.”

Jeter spent his career never looking any further ahead than the next game. It’s a mind-set that has served him well in collecting five World Series rings and building a Hall of Fame resume. But now there’s only one game left at Yankee Stadium, and even Jeter can’t downplay the significance.

All season, he has been treated to standing ovations during every at-bat, from Fenway to Camden Yards, from Safeco Field to Rogers Centre. Those receptions have intensified during this last month, and his Bronx home has turned into a cathedral of sorts for Jeter worship.

As impressive as that has been, expect that to be raised to another level by Thursday night’s sellout crowd.

“I think that people have shown him appreciation wherever he’s been this year,” Joe Girardi said. “For him to do it one more time in Yankee Stadium, I think is going to be special. I’ve talked about how special it is to put a uniform on, how special it is to put a Yankee uniform on. It’s very difficult to take it off.

“But I think tomorrow will be kind of a culmination of all the love that he’s been shown and all the appreciation that he’s been shown during the course of this year and in his career. And I think it will be something that we’ll remember for a long time.”

The tricky part for Girardi is balancing the natural progression of the night with a proper sendoff for the Yankees’ captain. He did it perfectly last season for Mariano Rivera’s final game. After “Enter Sandman” and the crowd-pleasing jog from the bullpen, Rivera got two quick outs before Girardi sent Jeter and Andy Pettitte to retrieve him from the mound.

Look for the Yankees to let Jeter take the field alone at the start of the game, in a way to soak up the adoration, and it’s a virtual lock Girardi will take him out at some point during the ninth inning as the closing act. Now that the Yankees have nothing left to play for in terms of the postseason, Girardi has free rein to focus on the Jeter-fest, even if he’s still formulating how to do it.

“I really don’t know,” Girardi said. “I think you kind of let it unwind, the day unwind, and see how it goes. And then you make some decisions as the day’s going on. I think that’s the best way to do it.”

Rain permitting, of course. As of Wednesday, Weather.com called for a 60-percent chance of showers at 7 p.m. That drops to 40 percent by 8 p.m. and 30 percent at 9 p.m.

Rest assured Major League Baseball will do everything within its power to make sure the game is played — regardless of the delay — because a makeup on Monday would be a logistical headache for everyone involved if it was needed to determine the AL’s best record for the playoff-bound Orioles. Ultimately, it will be MLB’s call on whether Jeter’s final home game is played tonight.

“I heard that it’s supposed to rain, but I’m not a meteorologist,” Jeter said. “So hopefully it cooperates.”

A year ago, Rivera decided that the Jeter-Pettitte moment was how he wanted to go out as a Yankee and passed on playing in Houston, despite Girardi’s willingness to give him an inning in centerfield.

That surprised Girardi. The manager said he will speak with Jeter before Thursday night’s game to discuss the plan for Fenway. Jeter had no interest in going there after yesterday’s loss and chided a reporter for asking about it.

“Respect the fact that we just lost — we’re not going to the playoffs,” Jeter said. “I can’t think about Boston.”

The feeling in the clubhouse, however, is that Thursday won’t be Jeter’s last game. Regardless of the weather.

“If I had to guess, he’s going to want to play every game,” Brett Gardner said. “Because next week it’s all going to be over.”